Means for equalizing load on two end plates of inflatable reinforced packer



United States rPatent O Whitman D. Mounce, Houston, Tex., assigner, bymesne assignments, to Esso Research and Engineering Company, Elizabeth,N. J., a corporation of Delaware Application September 19, 1955, SerialNo. 535,001

2 Claims. (Cl. 166187) This invention relates to an improved wellpacker.

More particularly this invention relates to a novel structure forequalizing the load between an upper support and a lower support on awell packer utilized in well operations.

In well operations such as those carried out in the taking ofdrillrstern tests of the fluids in a subsurface formation, itis commonpractice to seal 01ml the producing subsurface formation by means of asingle packer if the subsurface formation is located. near or at thebottom of a borehole or to straddle the subsurface formation with aplurality of packers if the producing formation is located upwardly fromthe bottom of the borehole. However, many previous packers have beenunable to withstand the very high pressures found withina deep borehole.This is So because the pressure exertedI upon a packer after it has beeninflated is concentrated at an area of the expansible rubber memberwhich is located just above the lower support member causing the ruptureof the expansible rubber member in this area.

It is an object, therefore, of this invention to provide a means forequally distributing the hydrostatic pressures exerted upon a packerbetween the upper support member and the lower support member.

Briefly described my new invention consists of an inflatable tubularmember which is mounted on a shaft by means of a first support memberand a second support member, with said support members being adapted tomove longitudinally toward one another when the inflatable member isbeing inflated. Means are provided within the inflatable member forequalizing the load exerted upon the packer after it has becomeinflated.

Other objects and a fuller understanding of the invention may be had byreferring to the following description and claims, taken in conjunctionwith the accompanying drawings in which:

Fig. 1 is a sectional elevational view showing my new packer in thedeflated position;

Fig. 2 is a sectional elevational view similar to Fig. 1 showing my newpacker in the inflated position; and

Fig. 3 is an elevational view of my new load equalizing member.

Referring more particularly to the drawings numeral 10 indicates aborehole into which my new inflatable packer has been inserted. Thoughone inflatable packer is shown in the drawings it is to be understoodthat if desired a plurality of inflatable packers might be utilized. Infact, two of the improved packers may be used to straddle an interval orformation to be isolated and/or tested. Mounted upon a shaft or mandrel11 is an upper support member 12 and lower support member 13. Supportmembers 12 and 13 are spaced from one another longitudinally upon shaft11 and may be mounted coaxially with shaft 11. Shaft 11 is provided witha passageway 14 through which the fluids obtained from the subsurfaceformation being tested may be flowed and subsequently removed to theearths surface for examination through a pipe or tubing threadedlyconnected to tubular load transfer tube 22.

the mandrel or shaft 11. Mounted upon the upper support member 12 andthe lower support member 13 and coaxially about the shaft member 11 isan expansible tubular member 15. The expansible tubular member 15 mayhave embedded therein reinforcing means 16, which reinforcing means mayconsist of steel cables or in the alternative a braided reinforcing socksuch as the braided steel sock described in my co-pending patentapplication Serial No. 520,424, filed July 7, 1955.

The upper and lower support members 12 and 13 are each made up of twoparts, a substantially frustro-conical sleeve 17 and a wedging member18. The frustro-conical sleeves 17 have formed therein rounded outportions 19 and outwardly flaring portions 20. The rounded ont portions19 serve to embrace the inflatable rubber mem# ber 15. The rubber member15 is bonded to the sleeves 17 and also bonded to the wedging members18. The sleeve members 17 have threaded bores 21 formed there'- in. Thethreaded bores 21 are adapted to matingly receive the threaded upper andlower extremities of a rigid The load transfer tube 22 has threadedtherein, at each of its longitudinal extremities, a ring member 23. Ringmembers 23 engage longitudinally spaced shoulders 24 formed upon shaft11. Hence, it can be seen that the load transfer tube 22 i is preventedfrom moving longitudinally along shaft mem ber 11 but is permitted torotate about shaft 11.

Sleeve members 17 have extensions 30 of reduced di`- ameter. Slots 31are formed in the extensions 30 which slots are adapted to receive stopmembers -32. An in flaton fluid passageway 33 is provided within shaft11 and an inflation fluid port 34 is provided in the load transfer tube22 to permit the passage of inflation fluid into the space defined bythe load transfer tube 22 and the expansible tubular member 15. Theinflation fluid is supplied by means of a pump (not shown). The pump maybe located within the tubing to which mandrel 11 is connected or it maybe at the surface of the earth.

When my new packer is deflated a space 3S is provided between thelongitudinal extremity of the load transfer tube 22 and the bottom ofthe bores 3S within sleeve members 17. This arrangement permits thelongitudinal movement of the support members toward one another as thepacker is being inflated.

As shown in Fig. 3 the threaded portions of the load transfer tube 22are steeply pitched with one end of the load transfer tube 22 beingformed in a left handed thread and the other end of the load transfertube 22 being formed as a right handed thread, thus permitting themovable support members 12 and 13 to readily move toward one another asthe packer is inflated.

In operation, my new packer is first lowered into position within theborehole 10 and then inflated to seal off the subsurface formation whichit is desired to test. The packer may be lowered by lowering the tubingor by wireline. Inflation fluid is then pumped through inflation fluidpassageway 33 and port 34 to expand the tubular member 15 so as to sealoff the subsurface formation. As the tubular member 15 expands, the loadtransfer tube 22 will rotate about shaft member 11 as the supportmembers 12 and 13 move longitudinally toward one another. After thepacker has become inflated and a pressure differential exists acrosstubular member 15 any local strain caused by the pressure differentialwill be distributed by the load transfer tube 22. For example, whentaking drill-stem tests, the packer is in inflated condition and ahigher pressure exists above tubular member 1S than exists below tubularmember 15. Tubular member 15' or portions thereof move downwardly underthe pressure differential and thereby move support member 13 downwardly.Movement of support member 13 downwardly rotates tube 22 which movesuppe r s1.1 ppprt member 112 ,upwardly thereby equalizing the badbetwseathe ,subpart members and Preventing fun-Y ture of tubular member 15 andkinking of cables 16. Therefore, the inclusion of the load transferringmeans prgovidegsa packer Whiehis Yable to withstand higherpres- Asuresthap thepressures-.Which can be withstood by previl011,5 ,Wellpaeierfsandptherefore, is quite useful.

Aithoughl have described my invention with a ,cer tain degree ofvparticularity, yit is understood that the presentdisclosure has beenmade only by way of example and .that `numerous changes :in Athe detailsof construction `andthe combination and arrangement of parts may beresorted to without departing `from the spirit and the scope oftheinvention ashereinafter claimed.

What I wish toclaim as new and useful is:

1 Ign a well packer:V a shaft, first and second spaced apart -lsupportmembers slidably arranged on said shaft, a `rigid rotatable tubularmember surrounding said shaft vand texteiidirigbetween said Supportmembers, a fluid `in- :flatablge .member surrounding said Ytubularmember and connected `to said rst and second support members, means forinating said inflatable member, stop means on said ,shaft vadapted toprevent longitudinal movement of said tubular member, steep-pitchedright-handed mating threads interconnecting one end of said tubularmember andone of said support members and steep-pitchedleft-handedvmating `threads interconnecting the other end of isaid'tubular member and said other support member whereby movement of oneof said support members in one direction rotates said ltubular member tomove said other support member in an opposite direction, said directionsof movement of said support members being toward each other when saidinflatable member is inating and being away from each other after saidinflatable member has been inated when equalizing a load carried .bysaid `Support members .between said `support members.

2. In a well packer: a shaft, a rst support member slidably mounted uponsaid shaft and provided with a steep-pitched left-handed yscrew-threadedbore, a second support member slidably mounted upon said shaft andprovided with a steep-pitched right-handed screwthreaded bore, V saidfirst and second support members being spaced apart, an inflatablemember surrounding said shaft and connected to said rst and secondsupport members, said inflatable member being formed 'to provide greaterrigidity ,longitudinally than' laterally, .means ,for infiating saidinflatable -m emb er, a rigid tubular member mounted on said shaft, andfirst and second spaced apart stop means formed onsaid shaft adapted toprevent longitudinal movement of said tubular member, said tubularmember being provided with steep-pitched threads adjacentthe end thereofadapted to mate with the threaded bores of said .support members wherebymovement of one of said support members in one direction rotates saidtubular member to move said other support member in an oppositedirection, said direction of movement of said support membersbeingtoward each othery when said inflatable member is inilating-and'being Vaway from each other after said inatablefmember'hasbeeninflated when equalizing a load carried by said support membersbetween said support members.

References Cited in the vle of this patent UNITED STATES PATENTS

